Quick release mechanism for gear operated seat recliner

ABSTRACT

A gear operated seat recliner mechanism is described which is particularly useful in connection with motor vehicle occupant seats. The recliner permits the angle between the seat back and seat bottom to be varied as desired by the seat occupant. In accordance with this invention, the upper recliner structure pivots about the lower recliner structure and a quadrant component, which pivots with the upper recliner structure, includes a curved toothed rack. The rack meshes with a gear mounted to the lower recliner structure. A pawl is adjustable between an engaged position which fixes the seat back angle to a disengaged postion permitting the seat back angle to be changed relative to the seat bottom. This design improves over prior art designs in that it employs fewer parts, is less costly to produce, and further, permits very fine adjustments in the seat back angle.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of copending application Ser.No. 602,370, filed Apr. 20, 1984.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to a seat recliner mechanism and, moreparticularly, to a motor vehicle seat recliner mechanism which permitsthe seat back angle relative to the seat bottom to be varied inaccordance with the desires of the motor vehicle occupant.

Many motor vehicles are now being provided, as standard or optionalequipment, with seat recliner mechanisms which provide added comfort andconvenience for the vehicle occupants. Numerous types of seat reclinermechanisms are known to the prior art. For example, U.S. Pat. No.4,372,610, issued to A. J. Fisher, III et al on Feb. 8, 1983, describesa recliner employing a pair of meshing straight toothed racks. One ofthe racks is connected to the seat upper recliner structure through aquadrant component. Adjustment of the seat reclined angle isaccomplished by changing the meshed position of one rack with respect tothe other which is accomplished by operating an actuator. Although suchdevices perform satisfactorily, it is desirable to provide a seatrecliner mechanism which is lighter in weight, less costly, and whichprovide smaller graduations between adjusted positions of seat backangle. It is further desirable to provide a seat recliner mechanismwhich provides a positive change in operating mode between engaged anddisengagement thereby avoiding objectionable ratcheting as the reclineractuator is moved between positions. Additionally, it is necessary tosecurely fix the seat back position to prevent inadvertent changes inseat back position.

A seat recliner mechanism in accordance with this invention employs acurved toothed rack on a component which rotates with the upper reclinermechanism and which meshes with a gear that is rotatable within thelower recliner mechanism. Locking of the seat back is achieved bycausing teeth of a pawl to engage the gear. Adjustments of seat backangle are provided when the toothed pawl is withdrawn from engagementwith the gear, thereby permitting gear rotation as the upper reclinermechanism and the seat back rotate about their pivot point. The abovedesign features are provided in accordance with the invention describedby copending U.S. patent application Ser. No. 602,370, filed Apr. 20,1984, which is assigned to the assignee of this invention and which ishereby incorporated by reference. This invention further discloses theaddition of components which provides a quick release feature enablingthe recliner locking mechanism to rapidly change from an engaged to adisengaged position.

The recliner mechanism according to this invention is usable for motorvehicle seats which are installed in two or four door type cars. In fourdoor models, the front seat back does not need to be folded forward topermit access to the rear seat occupant area. However, in two doordesigns having a rear seat occupant area, such provisions are necessary.Therefore, this invention is described in conjunction with an inertiasensitive seat back locking device according to prior art designs whichnormally permit seat back folding but act to prevent folding when thevehicle is subjected to deceleration above a predetermined thresholdlevel. The inertia sensitive seat back locking system shown inconjunction with this invention is also detailed by the previouslymentioned issued U.S. patent.

Additional benefits and advantages of the present invention will becomeapparent to those skilled in the art to which this invention relatesfrom the subsequent description of the preferred embodiments and theappended claims, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of the quick release gear operatedseat recliner according to the teachings of the present invention;

FIG. 2 is a bottom view of the seat recliner mechanism shown by FIG. 1;

FIG. 3 is a front elevational view of the seat recliner mechanism shownby FIG. 1;

FIG. 4 is a partial side view of the recliner components shown in aposition wherein the seat back is locking at a particular seat backangle; and

FIG. 5 is a partial side view of the recliner components shown in aposition permitting the seat back angle to be adjusted.

DETAILED DESCRIPTION OF THE INVENTION

A motor vehicle seat recliner mechanism according to this invention isshown assembled in FIGS. 1, 2 and 3 and is generally designated there byreference character 10. The embodiment of recliner mechanism 10described herein by the accompanying Figures is intended to bepositioned at the righthand side of a motor vehicle's passenger's seat.A recliner structure useful for a front driver's seat would preferablyemploy components which are mirror image replications of those describedherein. Recliner 10 includes lower recliner structure 12 which isattached to a seat bottom frame (not shown). Upper recliner structure 14is attached to the seat back frame (not shown) and is adapted to pivotwith respect to lower structure 12 about pivot pin 16. Lower reclinerstructure 12 is fabricated by attaching two plates, inner lower reclinerplate 18 and outer lower recliner plate 20. These plates are attachedtogether by rivets and define a space therebetween within whichadditional components, which will hereinafter be described, areinstalled. Recliner upper structure 14 is similarly fabricated byattaching two plates, inner upper recliner plate 22 and outer upperrecliner plate 24. These plates are also formed to define a spacetherebetween.

Journaled to pivot pin 16 is quadrant 26. The position of quadrant 26establishes the angular position of upper recliner structure 14 withrespect to lower recliner structure 12, and therefore, between the seatback and bottom. As shown by the Figures, quadrant 26 includes arcuateslot 28. Pin 30 is attached to upper recliner structure 14 and travelswith slot 28. The angular extent of slot 28 therefore defines themaximum extent of angular folding of the upper recliner structure. Forfour door models where a seat back folding mechanism is unnecessary,quadrant 26, or its functional equivalent, is fastened directly to upperrecliner structure 14 or is made integral therewith.

In accordance with a principal feature of this invention, quadrant 26includes curved toothed rack 32 along its lower edge. Toothed rack 32 isformed along a circular path having a center about pivot pin 16. Gear 34is rotatable about pivot pin 36 which is attached to lower reclinerstructure 12 and meshes with toothed rack 32. Preferably, gear 34includes a stepped external surface forming first diameter gear section38 and second diameter gear section 40. As shown by FIG. 1, firstdiameter gear section 38 has a diameter less than that of seconddiameter section 40. Pivot pin 36 cooperates with bore 42 of gear 38 topermit free rotation of the gear. Gear 34 is positioned so that toothedrack 32 meshes with first diameter gear section 38, thereby causingrotation of the gear as the angular position of quadrant 26 is changedwith respect to pivot pin 16.

Fixing of the position of quadrant 26 is achieved by causing toothedsurface 46 of pawl 44 to engage second diameter gear section 40. Pawl 44is restrained from moving when engaged with gear 34 since it ispivotably mounted about pivot pin 48. Pawl 44 is caused to move betweena position of engagement with gear 34 shown by FIGS. 1 and 4 to adisengaged position shown by FIG. 5 by providing recliner actuator 50which includes handle 52 and which is rotatable about pivot pin 54.Pivot pin 54 is journalled onto camplate 55 such that the camplaterotates with rotation of the pivot pin. Camplate 55 includes notch 56forming a cam surface. Pivot pin 54 is further journalled onto quickrelease cam 57 which includes a protruding resilient arm 58 and anotched engaging portion 59. The internal bore 61 of quick release cam57 is configured such that the cam is not caused to rotate until apredetermined degree of counterclockwise rotation of handle 52 and camplate 55 occurs. Once this predetermined amount of rotation occurs,continued lifting of handle 52 causes counterclockwise rotation of quickrelease cam 57. Such rotation occurs until notched engaging portion 59of quick release cam 57 clears tab 47 of pawl 44 thereby permittingrotation of the pawl about pivot 48. Rotation of pawl 44 results fromthe clockwise biasing force applied by spring 62. Once pawl 44 rotatesaway from engagement, the seat back reclined position can be adjustedsince quadrant 26 is then free to rotate. The predetermined degree ofangular motion of handle 52 with respect to quick release cam 57 ischosen such that, once this degree of rotation is achieved, camplate 55has been rotated a sufficient degree to permit clockwise rotation ofpawl 44. Due to the employment of quick release cam 57 and the biasforce of spring 62, pawl 44 releases rapidly from contact with gear 34,thereby preventing any ratcheting which might occur if the pawl weregradually released from engagement with the gear.

When handle 52 is returned to its normal position, the interaction ofnotch 56 and pin 60 which is fixed to pawl 44 forces re-engagementbetween the pawl and gear 34. Resilient arm 58 of quick release cam 57provides a constant clockwise rotational urging force on the cam.Internal bore 61 of quick release cam 57 is relieved such that a certaindegree of "lost motion" is permitted, enabling actuator pivot pin 54 tobe rotated without rotating quick release cam 57. Therefore, once pawl44 is positioned into engagement with gear 34, quick release cam 57notched engaging portion 59 returns into engagement with pawl tab 47.Once engaging portion 59 engages pawl tab 47, the pawl is securelypositioned into engagement with gear 34, thereby preventing inadvertentchanges in seat back reclined position unless recliner actuator 50 ismoved. Recliner actuator 50 is normally positioned to cause engagementbetween pawl 44 and gear 34 by providing spring 65 which biases reclinerhandle 52 in a clockwise direction. In the event of failure of quickrelease cam 57 or spring 62, the recliner mechanism remains operablesince notch 56 of camplate 55 will continue to guide pawl 44 into andout of engagement with gear 34 as actuator 50 is rotated.

Adjustment of the position of the seat back is simplified by providingpivot pin spring 64 which engages pivot pin 16 and lower reclinerstructure 12 thereby resiliently biasing the seat back in a clockwiseforward position, with respect to the orientation shown by FIG. 1. Suchbiasing permits the occupant to easily adjust the seat back positionwhile seated simply by raising recliner handle 52 and pushing againstthe seat back until the desired angular position is obtained, whereuponthe recliner handle is released to its normal position. Fine adjustmentof the angular position of upper recliner structure 14 is provided byusing very fine pitch teeth on second diameter gear section 40 and pawltoothed section 46. Such components provide smaller steps betweenadjusted positions as toothed surface 46 engages with successive teethalong second diameter gear section 40. The provision of an enlargedsecond diameter gear section 40 enables smaller pitch teeth to be usedsince the enlarged diameter results in a lowered requirement of forcerestraint between toothed surface 46 and second diameter gear section40.

Since it is desirable to limit the maximum range of recliner angularpositions, slot 66 is provided within quadrant 26. Pin 68, which isattached to lower recliner structure 12, travels within slot 66 andlimits the maximum degree of angular reclined position between upperrecliner structure 14 and lower recliner structure 12.

For use in two door car models, motor vehicle seat recliner 10 accordingto this invention further features inertia sensitive actuator 72 whichprevents forward rotation of the seat back during conditions of suddendeceleration of the associated motor vehicle. Inertia sensitive actuator72 of vehicle recliner 10 interacts with quadrant 26 and responds tovehicle deceleration to prevent forward displacement of the seat back.Actuator 72 includes upper weighted section 74, lower engaging portion76 with bore 78 therebetween. Upper weighted section 74 includes fixedweight 80 and rolling weight 82, which is permitted to roll within slot84 in response to vehicle deceleration. Pivot pin 86 is attached toupper recliner structure 14 and passes through bore 78 and cooperate toform a low friction bearing permitting free rotation of actuator 72. Theactuator is configured such that its centroid of mass (center ofgravity) lies above pivot pin 86 so that, upon vehicle deceleration,rolling weight 82 moves forward within slot 84 and the actuator iscaused to rotate in a clockwise direction, with respect to theorientation shown by FIG. 1. Engaging portion 76 of actuator 72 supportsengaging pin 88. Engaging pin 88 is retained in association withengaging section 76 since it is trapped between locally deformedportions 90 and 92 which form slots 94 and 96 respectively, within upperrecliner plates 22 and 24. Quadrant 26 includes a notched upper portiondefining stop surface 98. Therefore, when a predetermined level ofvehicle deceleration is sensed by actuator 72, the forward movement ofupper recliner structure 14 is limited due to engagement betweenengaging pin 88 and stop surface 98. Forward movement of upper reclinerstructure 14 in this situation is prevented due to engagement ofengaging pin 88 with stop surface 98 of quadrant 26, and the edges ofslots 94 and 96. Under normal circumstances, the seat back may be freelyrotated forward, since engaging pin 88 is permitted to escape engagementwith surface 98. Such escapement is provided by placement of thecentroid of mass (center of gravity) of actuator 72 such that theactuator is normally biased by gravity in a counterclockwise direction.

In order to provide enhanced reliability of engagement between actuator72 and stop surface 98, curved quadrant surface 112 is provided whichcontacts the actuator such that it is biased clockwise when the seatback is in its rearmost position. Slight forward rotation of the seatback relieves this bias and enables actuator 72 to either cause theengaging pin 88 to escape engagement with stop surface 98, or engagewith the stop surface in response to vehicle deceleration.

An emergency releasing mechanism is provided to enable rear seatoccupants to extract themselves from the vehicle in the event of failureof the inertia sensitive components of the seat recliner or in the eventthat vehicle inclination causes the hinge mechanism to latch. Therefore,release actuator 114 is provided having a rearwardly projecting portion116 which may be rotated about pivot pin 118 by the rear seat occupantsso that the release actuator is caused to rotate in a counterclockwiseposition about pivot pin 86, thereby withdrawing engaging pin 88 fromengagement with stop surface 98 and permitting the seat back to befolded forward.

While the above description constitutes the preferred embodiments of thepresent invention, it will be appreciated that the invention issusceptible to modification, variation and change without departing fromthe proper scope and fair meaning of the accompanying claims.

What is claimed is:
 1. A seat recliner mechanism supporting a seat backand seat bottom which permits the angle therebetween to be controllablyvaried comprising:a lower recliner structure, an upper reclinerstructure, first pivot means rotatably attaching said lower reclinerstructure to said upper recliner structure, a toothed rack operativelyconnected to one of said upper or lower recliner structures, secondpivot means carried by the other of said upper or lower reclinerstructures, gear means mounted to said second pivot means for rotationthereabout, said toothed rack meshing with said gear means, pawl meansfor engaging said gear means to control rotation of said gear means,third pivot means connected to said other of said upper or lowerrecliner structures, a recliner actuator rotatable about said thirdpivot means between a normal position and a released position, quickrelease cam means rotatable about said third pivot means, said quickrelease cam means coupled to said recliner actuator, lost motion meanscoupling said recliner actuator to said quick release cam means suchthat said quick release cam means is caused to rotate once the rotationof said recliner actuator from said normal position toward said releasedposition exceeds a predetermined angular displacement, said quickrelease cam means having an engagement portion which cooperates withsaid pawl means such that when said recliner actuator is in said normalposition, said engagement portion engages said pawl means and tomaintain said pawl means in a position to engage said gear means andwhen said recliner actuator is moved toward said released position, saidquick release cam means is rotated such that said engagement portiondisengages said pawl, said quick release cam means permitting said pawlmeans to move from an engaged to a disengaged position quickly, and acamplate rotatable with said recliner actuator, said camplate having acam surface which cooperates with said pawl means to urge said pawlmeans into engagement with said gear means when said recliner actuatoris rotated from said released position to said normal position.
 2. Aseat recliner mechanism according to claim 1 wherein said toothed rackis operatively connected to said upper recliner structure and saidsecond pivot means is connected to said lower recliner structure.
 3. Aseat recliner mechanism according to claim 2 further comprising stopmeans for limiting the maximum extent of angular travel between saidseat bottom and seat back.
 4. A seat recliner mechanism according toclaim 1 wherein said toothed rack is curved along a circular path havinga radius about said first pivot means.
 5. A seat recliner mechanismaccording to claim 1 wherein said gear forms first and second tootheddiameter sections, said first diameter section meshing with said toothedrack, said second diameter section engageable with said pawl means.
 6. Aseat recliner mechanism according to claim 5 wherein the diameter ofsaid first diameter section is less than the diameter of said seconddiameter section.
 7. A seat recliner mechanism according to claim 1wherein said pawl means pivots about a fourth pivot means.
 8. A seatrecliner mechanism according to claim 1 wherein said quick release cammeans further includes biasing means biasing said quick release cammeans toward an angular position wherein said engagement portion engagessaid pawl means.
 9. A seat recliner mechanism according to claim 8wherein said biasing means comprises a resilient arm operativelyassociated with said quick release cam means, said resilient arm furthercontacting said pawl means.
 10. A seat recliner mechanism according toclaim 1 further comprising biasing means biasing said pawl means towarda position wherein said pawl means is disengaged from said gear.
 11. Aseat recliner mechanism according to claim 1 wherein said quick releasecam engagement portion forms a notch which contacts a tab formed by saidpawl means.
 12. A seat recliner mechanism according to claim 1 whereinsaid camplate cam surface cooperates with a pin projecting from saidpawl means.
 13. A seat recliner mechanism according to claim 1 whereinsaid camplate cam surface is formed by a notch which acts to pull saidpawl means from engagement with said gear when said recliner actuator ismoved to said second position in the event of mechanical failure of saidquick release cam.
 14. A seat recliner mechanism according to claim 1wherein said recliner actuator is biased toward said first position. 15.A seat recliner mechanism supporting a seat back and seat bottom whichpermits the angle therebetween to be controllably varied comprising:alower recliner structure, an upper recliner structure, first pivot meansrotatably attaching said lower recliner structure to said upper reclinerstructure, a quadrant operatively connected to said upper reclinerstructure, said quadrant pivotable about said first pivot means, saidquadrant having a curved toothed rack, second pivot means carried bysaid lower recliner structure, gear means mounted to said second pivotmeans for rotation thereabout, said toothed rack meshing with said gearmeans, pawl means having one or more teeth for engagement with said gearmeans to control rotation of said gear means, third pivot meansconnected to said lower recliner structure, a recliner actuatorrotatable about said third pivot means between a normal position and areleased position, quick release cam means rotatable about said thirdpivot means, said quick release cam means coupled to said reclineractuator, lost motion means coupling said recliner actuator to saidquick release cam means such that said quick release cam means is causedto rotate once the rotation of said recliner actuator from said normalposition to said released position exceeds a predetermined angulardisplacement, said quick release cam means having an engagement portionwhich cooperates with said pawl means such that when said reclineractuator is in said normal position, said engagement portion engagessaid pawl means to cause said pawl means to engage said gear means andwhen said recliner actuator is moved toward said released position, saidquick release cam means is rotated such that said engagement portiondisengages said pawl means, said quick release cam means permitting saidpawl means to move from an engaged to a disengaged position quickly, anda camplate rotatable with said recliner actuator, said camplate having acam surface which cooperates with said pawl means to urge said pawlmeans into engagement with said gear means when said recliner actuatoris rotated from said released position to said normal position.
 16. Aseat recliner mechanism according to claim 15 further comprising stopmeans for limiting the maximum extent of angular travel between saidseat bottom and seat back.
 17. A seat recliner mechanism according toclaim 15 wherein said gear forms first and second toothed diametersections, said first diameter section meshing with said toothed rack,said second diameter section engageable with said pawl teeth.
 18. A seatrecliner mechanism according to claim 17 wherein the diameter of saidfirst diameter section is less than the diameter of said second diametersection.
 19. A seat recliner mechanism according to claim 15 whereinsaid pawl pivots about a fourth pivot means.
 20. A seat reclinermechanism according to claim 15 wherein said quick release cam furtherincludes biasing means biasing said quick release cam toward an angularposition wherein said notched engaging portion engages said pawl.
 21. Aseat recliner mechanism according to claim 15 wherein said biasing meanscomprises a resilient arm operatively associated with said quick releasecam, said resilient arm further contacting said pawl.
 22. A seatrecliner mechanism according to claim 15 further comprising biasingmeans biasing said pawl toward a position wherein said pawl isdisengaged from said gear.
 23. A seat recliner mechanism according toclaim 15 wherein said quick release cam engaging portion forms a notchwhich contacts a tab formed by said pawl.
 24. A seat recliner mechanismaccording to claim 15 wherein said camplate cam surface cooperates witha pin projecting from said pawl.
 25. A seat recliner mechanism accordingto claim 15 wherein said camplate cam surface is formed by a notch whichacts to pull said pawl from engagement with said gear when said reclineractuator is moved to said second position in the event of mechanicalfailure of said quick release cam.